brain sizes: Einstein's and women's

John Knight johnknight at usa.com
Wed Jul 10 02:24:10 EST 2002


"Mark D. Morin" <mdmpsyd at NOSPAMgwi.net> wrote in message
news:3D2BA223.4020605 at NOSPAMgwi.net...
> >>>Most of the corrlations I've gotten are in the range of 0.6, so it
would
> >>>really be appreciated if you could provide a reference to the above.
> >>
> >>0.6 is not a low correlation--it explains over one third of the
> >>variation in scores.  In any other field, an R of this size would be
> >>considered robust.
> >>
> >>my resources are at the office, I'll dig them out today.
> >>
> >
> >
> > Yes, 0.6 really is good correlation, but when compared to the 0.8795
> > correlation between brain size and GRE Quantitative, you have to wonder
> > what's missing from "IQ tests".
>
> and there still isn't a reliable source for this statistic.
>


For which statistic?  Are you questioning Philippe Rushton's measurements of
brain size, GRE Quantitative Scores, or the method for calculating
r-squared?

Run the data at http://christianparty.net/grebrainsize.htm yourself.  Or use
the following figures and see what you get for r-squared.  The first column
of numbers is brain size in cubic centimeters, and the second column is GRE
Quantitative Scores

Asian men 1,472 638
White men 1,416 586
Asian women 1,358 572
White women 1,308 514
African men 1,319 446
African women 1,217 404


If you manage to get something much different than 0.87 to 0.88, please let
me know how you did it.

Just comparing the highest score to the lowest score you could argue that
each 1 cc increase in brain size is equivalent to a 1 point increase in GRE
Scores, which is not insignificant.

If you remove the furthest outlier, which is  Black men's brains [no pun
intended], then r-squared increases to 0.9583.  Such a small variation could
easily be due to errors in either measurement rather than some other unknown
factor.  For example, Indian men scored 14 points higher in 1998 than they
did in 1997, whereas Puerto Rican women scored 6 points lower, for a 20
point swing relative to each other.  Usually the variation from year to year
is only about 4 points, but because of this variation, brain size may be a
more accurate measurement of someone's quantitative ability than the GRE
Quantitative score itself );

John Knight





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